AD, a leading health problem for this country, affects 5-l0 percent of those over 65. By the year 2000, this aging population will double. A test permitting a definitive and early diagnosis of AD is greatly needed. Athens Research and Technology, Inc. (ART), proposes to develop such a diagnostic test using MAbs it has raised to a modified form of AlX. In Phase I study, ART will characterize its MAbs, design a pilot immunoassay, and evaluate the assay's diagnostic potential using cerebrospinal fluid (CSF) and plasma samples from normal persons and patients with AD. If Phase I studies are successful, in Phase II project, the assay will be developed as a commercial test. The availability of a diagnostic test for AD is clearly important. Early diagnosis of AD would lead to better management of AD patient care. An accurate diagnostic test would assist researchers developing and evaluating AD therapies. Finally, in the event a therapy is discovered, the test could be used to monitor the efficacy of the treatment in AD patients.